Orthotic or orthopaedic devices to which the present invention relates operate to support and brace injured limbs, muscles, joints and bones. The term "orthosis" or "orthotic device" as used herein differs from a "prosthesis" or "prosthetic device" insofar as a "prosthesis" is generally defined as an artificial device used to replace a missing body part or limb.
It is extremely common that people, especially physically active and frail elderly people, experience a variety of lower leg, ankle and foot injuries. For example, sprains to the calcaneofibular and anterior tabofibular ligaments often afflict a number of professional and amateur athletes.
To aid in the proper healing and treatment of these and other lower leg and foot injuries it is necessary that the affected areas, as well as the surrounding tissue, be stabilized and immobilized.
Physicians traditionally have treated, and still currently treat, injuries affecting lower leg extremities and the foot by fitting the injured patient with the well-known, molded plaster or resin cast, which is set around an inner cotton or gauze lining. The placement of this type of cast around the lower leg is time consuming, heavy, and costly.
The injured limb or joint is usually swollen when the plaster or resin cast is initially applied. One drawback of the traditional plaster cast is that the swelling of the injured limb usually decreases soon after the rigid cast is fitted and set around the limb. In addition, the range of swelling is directly related to the position of the leg. For example, if the leg is in a position whereby the patient is standing upright, the blood flows to the bottom of the leg and foot, thus causing additional swelling. Conversely, if the leg is positioned in a horizontal or elevated position the blood may backflow to the heart, thereby decreasing the amount of swelling. Therefore, the initial rigid cast is unable to compensate for this fluctuation of swelling and is often inappropriate to effectively stabilize and immobilize the injured limb or joint once the swelling has been reduced, and a second cast must be applied in order to subsequently conform to the less swollen portion of the anatomy.
In addition, it is virtually impossible to bathe in the normal manner while wearing a plaster cast. In order to bathe in a plaster cast, one must prevent any part of the cast from becoming moist since wetting the cast will make the cast soft and somewhat mushy. Furthermore, if the cast becomes wet or moist, the cast tends to fall apart.
Another disadvantage of the plaster or resin cast is that these types of casts cause the skin covered by the cast to become irritated, flaky and dry, thus, resulting in an uncomfortable itching sensation which often cannot be reached and relieved.
Also, the rigid nature of the cast and its relatively tight fit, inhibits proper circulation of blood and lymphatic fluid to and from the muscles of the leg resulting in the affected limb becoming atrophied and temporarily dysfunctional. If atrophying occurs, the patient must often undergo extensive rehabilitative treatment under the supervision of a physician or physical therapist in order to exercise and strengthen the atrophied limb. Rehabilitation therapy, although necessary, is a costly and time consuming procedure.
Many devices and orthotics relating to lower leg and ankle injuries have been proposed as an alternative to plaster casts in an effort to either cut down on the weight, decrease the bulkiness or improve the comfort for the user. Certain brace or casts of this type are set forth in the prior art. While, in whole or in part, these patented orthopaedic casts and/or braces claim to be lightweight or portable or an improvement over the traditional plaster casts, all of these devices, in fact, leave considerable room for improvement. For example, the Mauldin "Lower Leg Brace," U.S. Pat. No. 4,572,169, shows a removable ankle brace. This brace, however, must be worn at all times during the healing process of the injured limb, except while bathing. Therefore, all of the dirt that is acquired while wearing this brace is brought into bed since the patient must wear this brace while he or she is asleep. Wearing this brace while asleep may also cause the user considerable discomfort due to its bulkiness.
Another disadvantage of the Mauldin '169 brace is that the sole is designed and constructed in such a way that it unnecessarily requires extra material and is relatively high in cost and heavy. The Mauldin '169 brace also fails to provide a heel-strike portion capable of successfully absorbing shock to the afflicted limb.
Another device which attempts to immobilize and protect injured limbs or joints is the Johnson, "Orthopedic Apparatus," U.S. Pat. No. 3,955,565. The Johnson '565 device is essentially comprised of a pair of complimentary half-shell members having a series of pneumatics disposed throughout the interior surface of each half-shell. The half-shells are mated together, around the injured limb, and secured by VELCRO fastening straps. Subsequently, the air bags or pneumatics are inflated until they conform to the shape of the limb.
A disadvantage of the device described in the Johnson '565 patent is that the entire device must be worn to bed by the patient. Wearing this brace may cause considerable discomfort, like the Mauldin '169 patent, due to its bulkiness. In addition, as in the Mauldin '169 patent, the Johnson patent also fails to provide a means for successfully absorbing shock to the injured limb while walking.